The Agricultural Marketing Service of the US Department of Agriculture has moved to tighten its oversight of the expanding organic food industry. Under a final rule published in the Federal Register on Nov. 8, beginning in 2013, accredited certifying agents of the AMS’s National Organic Program will be required to visit annually no fewer than 5 percent of the farms and businesses they certified as organic to ensure products, production methods and premises remain free from residues of prohibited substances and in compliance with NOP regulations.